float2str converts floating point numbers to a character array. Its purpose is to have a character representation of floating point numbers when printf floating point support is not enabled by compiler options.
float2str.h@0:d8558b73ffd7, 2016-09-02 (annotated)
- Committer:
- jensstruemper
- Date:
- Fri Sep 02 15:04:03 2016 +0000
- Revision:
- 0:d8558b73ffd7
- Child:
- 1:89abb5f1c2fd
initial commit;
Who changed what in which revision?
User | Revision | Line number | New contents of line |
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jensstruemper | 0:d8558b73ffd7 | 1 | /* |
jensstruemper | 0:d8558b73ffd7 | 2 | Copyright (c) 2016 Jens Strümper |
jensstruemper | 0:d8558b73ffd7 | 3 | |
jensstruemper | 0:d8558b73ffd7 | 4 | Permission is hereby granted, free of charge, to any person obtaining a copy |
jensstruemper | 0:d8558b73ffd7 | 5 | of this software and associated documentation files (the "Software"), to deal |
jensstruemper | 0:d8558b73ffd7 | 6 | in the Software without restriction, including without limitation the rights |
jensstruemper | 0:d8558b73ffd7 | 7 | to use, copy, modify, merge, publish, distribute, sublicense, and/or sell |
jensstruemper | 0:d8558b73ffd7 | 8 | copies of the Software, and to permit persons to whom the Software is |
jensstruemper | 0:d8558b73ffd7 | 9 | furnished to do so, subject to the following conditions: |
jensstruemper | 0:d8558b73ffd7 | 10 | |
jensstruemper | 0:d8558b73ffd7 | 11 | The above copyright notice and this permission notice shall be included in |
jensstruemper | 0:d8558b73ffd7 | 12 | all copies or substantial portions of the Software. |
jensstruemper | 0:d8558b73ffd7 | 13 | |
jensstruemper | 0:d8558b73ffd7 | 14 | THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR |
jensstruemper | 0:d8558b73ffd7 | 15 | IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, |
jensstruemper | 0:d8558b73ffd7 | 16 | FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE |
jensstruemper | 0:d8558b73ffd7 | 17 | AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER |
jensstruemper | 0:d8558b73ffd7 | 18 | LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, |
jensstruemper | 0:d8558b73ffd7 | 19 | OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN |
jensstruemper | 0:d8558b73ffd7 | 20 | THE SOFTWARE. |
jensstruemper | 0:d8558b73ffd7 | 21 | */ |
jensstruemper | 0:d8558b73ffd7 | 22 | |
jensstruemper | 0:d8558b73ffd7 | 23 | #ifndef MBED_H |
jensstruemper | 0:d8558b73ffd7 | 24 | #include "mbed.h" |
jensstruemper | 0:d8558b73ffd7 | 25 | #endif |
jensstruemper | 0:d8558b73ffd7 | 26 | |
jensstruemper | 0:d8558b73ffd7 | 27 | #ifndef FLOAT2STR_H |
jensstruemper | 0:d8558b73ffd7 | 28 | #define FLOAT2STR_H |
jensstruemper | 0:d8558b73ffd7 | 29 | |
jensstruemper | 0:d8558b73ffd7 | 30 | namespace js { |
jensstruemper | 0:d8558b73ffd7 | 31 | |
jensstruemper | 0:d8558b73ffd7 | 32 | /** float2str converts floating point numbers to a character array. Its purpose is to |
jensstruemper | 0:d8558b73ffd7 | 33 | * have a character representation of floating point numbers when printf floating point support |
jensstruemper | 0:d8558b73ffd7 | 34 | * is not enabled by compiler options. |
jensstruemper | 0:d8558b73ffd7 | 35 | * |
jensstruemper | 0:d8558b73ffd7 | 36 | * This is done by: . |
jensstruemper | 0:d8558b73ffd7 | 37 | * <ul> |
jensstruemper | 0:d8558b73ffd7 | 38 | * <li> Separating the integer from the fract part of the floating point number. </li> |
jensstruemper | 0:d8558b73ffd7 | 39 | * <li> Casting both parts to integer </li> |
jensstruemper | 0:d8558b73ffd7 | 40 | * <li> Convert the integers to char arrays </li> |
jensstruemper | 0:d8558b73ffd7 | 41 | * <li> Add the "." seperator and padding zeros behind the "." </li> |
jensstruemper | 0:d8558b73ffd7 | 42 | * <li> return the compile charater array </li> |
jensstruemper | 0:d8558b73ffd7 | 43 | * </ul> |
jensstruemper | 0:d8558b73ffd7 | 44 | * The toString function takes two arguments: |
jensstruemper | 0:d8558b73ffd7 | 45 | * <ul> |
jensstruemper | 0:d8558b73ffd7 | 46 | * <li> Floating point number that shall be converted </li> |
jensstruemper | 0:d8558b73ffd7 | 47 | * <li> Number of digits after the "." </li> |
jensstruemper | 0:d8558b73ffd7 | 48 | * </ul> |
jensstruemper | 0:d8558b73ffd7 | 49 | * |
jensstruemper | 0:d8558b73ffd7 | 50 | * Only callbacks that have been attached will be called by the library. |
jensstruemper | 0:d8558b73ffd7 | 51 | * |
jensstruemper | 0:d8558b73ffd7 | 52 | * Example: |
jensstruemper | 0:d8558b73ffd7 | 53 | * @code |
jensstruemper | 0:d8558b73ffd7 | 54 | * #include "mbed.h" |
jensstruemper | 0:d8558b73ffd7 | 55 | * #include "float2str.h" |
jensstruemper | 0:d8558b73ffd7 | 56 | * |
jensstruemper | 0:d8558b73ffd7 | 57 | * float number = 13.467472; |
jensstruemper | 0:d8558b73ffd7 | 58 | * char *string; |
jensstruemper | 0:d8558b73ffd7 | 59 | * |
jensstruemper | 0:d8558b73ffd7 | 60 | * int main(){ |
jensstruemper | 0:d8558b73ffd7 | 61 | * |
jensstruemper | 0:d8558b73ffd7 | 62 | * while(1){ |
jensstruemper | 0:d8558b73ffd7 | 63 | * float number = static_cast <float> (rand()) / (static_cast <float> (100000)); |
jensstruemper | 0:d8558b73ffd7 | 64 | * charArray = toString (number, 5); |
jensstruemper | 0:d8558b73ffd7 | 65 | * printf ("Char Array: %s Float: %f \r\n", charArray, number ); |
jensstruemper | 0:d8558b73ffd7 | 66 | * wait(1); |
jensstruemper | 0:d8558b73ffd7 | 67 | * } |
jensstruemper | 0:d8558b73ffd7 | 68 | * @endcode |
jensstruemper | 0:d8558b73ffd7 | 69 | * |
jensstruemper | 0:d8558b73ffd7 | 70 | * This example will convert randomly generated floating point numbers to a character array of fixed lenght [10]. |
jensstruemper | 0:d8558b73ffd7 | 71 | * |
jensstruemper | 0:d8558b73ffd7 | 72 | */ |
jensstruemper | 0:d8558b73ffd7 | 73 | |
jensstruemper | 0:d8558b73ffd7 | 74 | |
jensstruemper | 0:d8558b73ffd7 | 75 | /* |
jensstruemper | 0:d8558b73ffd7 | 76 | ** reverse string in place |
jensstruemper | 0:d8558b73ffd7 | 77 | */ |
jensstruemper | 0:d8558b73ffd7 | 78 | void reverse(char *s) { |
jensstruemper | 0:d8558b73ffd7 | 79 | char *j; |
jensstruemper | 0:d8558b73ffd7 | 80 | int c; |
jensstruemper | 0:d8558b73ffd7 | 81 | |
jensstruemper | 0:d8558b73ffd7 | 82 | j = s + strlen(s) - 1; |
jensstruemper | 0:d8558b73ffd7 | 83 | while(s < j) { |
jensstruemper | 0:d8558b73ffd7 | 84 | c = *s; |
jensstruemper | 0:d8558b73ffd7 | 85 | *s++ = *j; |
jensstruemper | 0:d8558b73ffd7 | 86 | *j-- = c; |
jensstruemper | 0:d8558b73ffd7 | 87 | } |
jensstruemper | 0:d8558b73ffd7 | 88 | } |
jensstruemper | 0:d8558b73ffd7 | 89 | /* |
jensstruemper | 0:d8558b73ffd7 | 90 | ** itoa: convert n to characters in s |
jensstruemper | 0:d8558b73ffd7 | 91 | */ |
jensstruemper | 0:d8558b73ffd7 | 92 | void itoa(int n, char s[]) |
jensstruemper | 0:d8558b73ffd7 | 93 | { |
jensstruemper | 0:d8558b73ffd7 | 94 | int i, sign; |
jensstruemper | 0:d8558b73ffd7 | 95 | |
jensstruemper | 0:d8558b73ffd7 | 96 | if ((sign = n) < 0) /* record sign */ |
jensstruemper | 0:d8558b73ffd7 | 97 | n = -n; /* make n positive */ |
jensstruemper | 0:d8558b73ffd7 | 98 | i = 0; |
jensstruemper | 0:d8558b73ffd7 | 99 | do { /* generate digits in reverse order */ |
jensstruemper | 0:d8558b73ffd7 | 100 | s[i++] = n % 10 + '0'; /* get next digit */ |
jensstruemper | 0:d8558b73ffd7 | 101 | } while ((n /= 10) > 0); /* delete it */ |
jensstruemper | 0:d8558b73ffd7 | 102 | if (sign < 0) |
jensstruemper | 0:d8558b73ffd7 | 103 | s[i++] = '-'; |
jensstruemper | 0:d8558b73ffd7 | 104 | s[i] = '\0'; |
jensstruemper | 0:d8558b73ffd7 | 105 | reverse(s); |
jensstruemper | 0:d8558b73ffd7 | 106 | } |
jensstruemper | 0:d8558b73ffd7 | 107 | |
jensstruemper | 0:d8558b73ffd7 | 108 | /* |
jensstruemper | 0:d8558b73ffd7 | 109 | ** toString: convert floating point number to |
jensstruemper | 0:d8558b73ffd7 | 110 | */ |
jensstruemper | 0:d8558b73ffd7 | 111 | |
jensstruemper | 0:d8558b73ffd7 | 112 | char *toString(float number, int digits) |
jensstruemper | 0:d8558b73ffd7 | 113 | { |
jensstruemper | 0:d8558b73ffd7 | 114 | int d1; |
jensstruemper | 0:d8558b73ffd7 | 115 | int d2; |
jensstruemper | 0:d8558b73ffd7 | 116 | char buf_d1[10]; |
jensstruemper | 0:d8558b73ffd7 | 117 | char buf_d2[10]; |
jensstruemper | 0:d8558b73ffd7 | 118 | static char buf_out[10]; |
jensstruemper | 0:d8558b73ffd7 | 119 | // char padzero[10]; |
jensstruemper | 0:d8558b73ffd7 | 120 | double fractpart, intpart; |
jensstruemper | 0:d8558b73ffd7 | 121 | int multiplier=1; |
jensstruemper | 0:d8558b73ffd7 | 122 | |
jensstruemper | 0:d8558b73ffd7 | 123 | for (int j=0; j < digits; j++){ |
jensstruemper | 0:d8558b73ffd7 | 124 | multiplier = multiplier * 10; |
jensstruemper | 0:d8558b73ffd7 | 125 | } |
jensstruemper | 0:d8558b73ffd7 | 126 | fractpart = modf (number , &intpart); |
jensstruemper | 0:d8558b73ffd7 | 127 | d2 = int(fractpart*multiplier); |
jensstruemper | 0:d8558b73ffd7 | 128 | d1 = int(intpart); |
jensstruemper | 0:d8558b73ffd7 | 129 | itoa(d1, buf_d1); |
jensstruemper | 0:d8558b73ffd7 | 130 | itoa(d2, buf_d2); |
jensstruemper | 0:d8558b73ffd7 | 131 | |
jensstruemper | 0:d8558b73ffd7 | 132 | strcpy(buf_out, buf_d1); |
jensstruemper | 0:d8558b73ffd7 | 133 | strcat(buf_out, "."); |
jensstruemper | 0:d8558b73ffd7 | 134 | |
jensstruemper | 0:d8558b73ffd7 | 135 | if (strlen(buf_d2) < digits) { /* adding n padding zero's if nessesary */ |
jensstruemper | 0:d8558b73ffd7 | 136 | for (int k=0; k < (digits - strlen(buf_d2)); k++){ |
jensstruemper | 0:d8558b73ffd7 | 137 | strcat(buf_out, "0"); |
jensstruemper | 0:d8558b73ffd7 | 138 | } |
jensstruemper | 0:d8558b73ffd7 | 139 | } |
jensstruemper | 0:d8558b73ffd7 | 140 | strcat(buf_out, buf_d2); |
jensstruemper | 0:d8558b73ffd7 | 141 | |
jensstruemper | 0:d8558b73ffd7 | 142 | return buf_out; |
jensstruemper | 0:d8558b73ffd7 | 143 | } |
jensstruemper | 0:d8558b73ffd7 | 144 | |
jensstruemper | 0:d8558b73ffd7 | 145 | }; |
jensstruemper | 0:d8558b73ffd7 | 146 | |
jensstruemper | 0:d8558b73ffd7 | 147 | using namespace js; |
jensstruemper | 0:d8558b73ffd7 | 148 | |
jensstruemper | 0:d8558b73ffd7 | 149 | #endif |